Standard methods for measuring FRC and compliance for the whole lung have been known for years (Meneely et al., Am. J. Med. 28:824–831 (1960); Darling et al., J. Clin. Invest. 19:609–618 (1940); Burns et al., Am. Rev. Respir. Dis. 130:580–583 (1984); Dubois et al., J. Clin. Invest. 35:322–326 (1956)). The use of hyperpolarized noble gases, such as 3He, has been demonstrated to be useful in the imaging of gas distribution (ventilation) in the human lung (Middleton et al., Mag. Res. Med. 33:271–275 (1995); MacFall et al., Rad. 200:553–558 (1996); Kauczor et al., Rad. 201:564–568 (1996); Kauczor et al, J. Mag. Res. Imag. 7:538–543 (1997); Roberts et al., Mag. Res. Med. 44(3):379–382 (2000); Black et al., Rad. 199(3):867–870 (1996); de Lange et al., Rad. 210(3):851–857 (1999); Altes et al., J. Mag. Res. Imag. 13(3):378–384 (2001); Salerno et al., Mag. Res. Med. 46:667–677 (2001); Gierada et al., NMR Biomed. 13(4): 176–18 1 (2000)). However, what has not been available until the present invention, has been a method for high resolution imaging of the gas spaces in the lung, with very high contrast between the signal intensity for the gas phase compared to the tissue phase, which would permit the combined imaging of FRC distribution and lung compliance.
The only known work in this field is related to imaging only the distribution of FRC by a single group Gattinoni et al., Am J Respir Crit Care Med 151:1807–1814 (1995)). The Gattinoni group used high resolution computer tomography (HRCT) methods to assess the gravitational distribution of FRC in patients with adult respiratory distress syndrome (ARDS). However, that work was limited by the limitations of the HRCT method. The “images” they obtained for distribution of FRC were fairly low in resolution, and more importantly, those images were only 2-dimensional. Moreover, the HRCT technique was not, and is not, capable of rapid measurements of FRC for the whole lung.
Thus, a need has remained in the art until the present invention for a method providing rapid imaging of FRC distribution for the whole lung; true 3 dimensional imaging; and very high resolution imaging of lung volumes and pulmonary compliance.